THE GOSSAMER-WINGED BUTTERFLIES 



(4) The late spring form, Cyaniris ladon ladon. — In the 

 southern part of the range of the species, i. e. south of lat. 

 40 on the Atlantic coast but as far north as Montana in the 

 West, there appears, from over-wintering chrysalids, but con- 

 siderably later than the forms described above, a fourth spring 

 form. This is the largest form of the species, expanding one 

 and four-tenths inches ; and the spots on the under side are 

 much smaller than in either of the preceding forms. This 

 form has been known as pseudargiolus ; but ladon is the older 

 name. 



(5) The summer form, Cyaniris ladon neglecta. — In the 

 more northern portions of the range of the species, i. e. north 

 of Montreal, this butterfly is single-brooded ; but south of that 

 region a second generation of butterflies is produced from eggs 

 laid by the spring forms. This generation appears in June, 

 and a third generation may appear in the fall. Both of these 

 generations are of the type known as neglecta. This form 

 resembles the late spring form in markings, but is smaller, not 

 expanding more than one and one-tenth inches. 



Mr. Scudder does not regard neglecta as distinct from C. 

 ladon ladon, or pseudargiolus as it has been more commonly 

 termed ; according to this view neglecta is one of the spring 

 forms as well as the summer form. And we have had diffi- 

 culty in separating the two by the characteristic of size as 

 given in the table above. 



The following table, based on the publications of Mr. W. 

 H. Edwards, indicates the distribution of the forms described 

 above : 



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